Production of antraquinone sulphonic acids



25 ency for the heat Patented -May 29, 1928.

UNITED STATES JOHN THOMAS, OF GARLISLE,

ENGLAND, ASSIGNOR TO SCOTTISH DYES, LIMITED,

GARLISLE, ENGLAND.

PRODUCTION OF AN'IBAQUINONE SULPHONIC ACIDS.

No Drawing. Application filed June 19, 1224, Serial No. 721,118, add in Great Britain August 31, 1923.

The invention deals with the production of alpha-sulphonic acids of anthraquinone. The object of the invention is toprovide an improved or modified process in which the materials are used in a very economical manner.

In order to prepare alpha-sulphonic acids of anthraquinone, a charge is made as follows, viz: Parts by weight Anthraquinone recovered from a previous melt 70 Benzoyl-ortho-benzoic acid 325 Oleum of 65 percent strength 45 Mercury sulphate 4.8

The mercury sulphate, benzoyl-ortho-benzoic acid and anthraquinone are mixed to-' gether and added to the oleum at such a rate that the temperature is not allowed to. exceed 100 C. After the addition is complete, the temperature is slowly raised to 150 C. and kept at 150 C. for 45 minutes. If the temperature is raised too quickly there is a tendof the reaction to raise the temperature above 150 C. when higher proportions of disulphonic acids are formed. The melt is poured into 3,000 parts water, boiled and filtered hot. The residue is again 9 boiled with 1,000 parts water, filtered and theu'nchanged anthraquinone is washed acid free anddried. y

To the combined filtrates 8 parts-of-caustic -potash are added, the mixture boiled, al-

lowed to cool and filtered. The potassium salt is washed acid free with 5 er cent potassium chloride solution, and t e wet aste is weighed and dried. The amount-o potassium chloride present can then be calcu-.

40 lated. The filtrates are now saturated with salt and the precipitated disulphonic acids filtered off, washed acid free with 25 per cent brine, the wet paste weighed and dried.

In the above, the yields were 83 parts of recovered anthraquinone, 270 parts of potassium salt of anthraquinone-alpha-sulphonic acid, 99 arts of sodium salts of anthraquinone 'sulphonie acids.

For the purposes of this invention in place. of benzoyl-ortho-benzoic acid itself derivatives of this body may be employed.

The mercury sulphate referred to herein is intended to refer to mercurous sulphate.

- Similarly where the word oleum is used the equivalent of oleum in sulphuric acid is included.

Having now described my invention what I claim as new and desire to secure by Letters Patent is:

1. A method for the production of oz-Slllphonic acids of anthraquinone which consists in mixing together about 4.8 parts of mercury sulphate, 325 parts of benzoyl-orthobenzoic acid, 70 parts of anthraquinone recovered froina previous melt and adding this mixture to about 450 parts of 65 per cent oleum at such a rate that the temperature is not allowed to exceed 100 C. and after the addition is complete slowly raising the temperature to about 150 C. and maintaining it there for about 45 minutes, subsequently workin up the melt, isolating anthraquinone su pho'nicacid and recovering anthr uinone. r

2. A met 0d for the production of a-sulphonic acids of anthraquinone which' consists in mixing together about 4.8 parts'of mercury sulphate, 325 parts vof benzoy ortho-benzoic" acid, '70 parts of anthraquinone recovered from a previous melt and adding this mixture to about 450 parts of 65 per cent oleum at such a rate that the temperature is not allowed to exceed 100 C. and after the addition is complete slowly raising the temperature to about 150- C. and maintaining it there for about 45 minutes, subsequently pouring the melt into about 3,000 parts of water, separating the precipitate, treating the filtrates with alkali, separating the alk li salt, treating this latter with sodium chloride and thus precipitating the sulphonic acids.

- In testimony whereof I have signed my name to this specification.

JOHN TiroMAs. 

